Manufactured products are made from atoms. The properties of those products depend on how those atoms are arranged. For instance, if the atoms in coal are rearranged, they may be used to form a diamond. Viewed from the molecular level, most manufactured articles are very crude and imprecise. Casting, grinding, milling, welding, and all other traditional manufacturing methods spray atoms in large groups. Even lithography is fundamentally statistical and random. Exactly how many dopant atoms are in a single transistor and exactly where each individual dopant atom is located is neither specified nor known.
Nanotechnology offers the ability to work at the atomic, molecular, and supramolecular levels, in a scale of about 1 to 100 nanometers, in order to create, manipulate, and use materials, devices, and systems that have novel properties and functions because of the small scale of their structures. Nanotechnology includes integration of nanoscale structures into larger architectures that may be used in industry, medicine, and environmental protection. Manipulating natural and artificial nano- and micro structures such as cell structures, nanowires, and nanosensors, will be critical to the integration of nanotechnology with device development and manufacturing.
The development of methods for organizing micro- and nanostructures into functional materials with addressable micro-nanoscopic components represents a significant challenge. A variety of methods have been employed to control the assembly of micro- and nanoparticles into ordered one-, two-, and three-dimensional architectures in solution and on surfaces. These invoke three general approaches: 1) the use of organic linker molecules and covalent bonding to generate meso- and macroscopic architectures with control over particle placement within an assembled network of particles; 2) the use of external physical forces (e.g. electric fields) and weak interactions to form ordered 2D particle arrays; and 3) the use of biological molecules and their molecular-recognition properties to guide the assembly of polymeric-network structures either on a surface or in solution.
Biorecognition offers the potential for highly selective nanoparticle positioning. DNA-directed assembly in particular has enormous potential in bottom-up assembly of complex micro- and nanoparticle architectures. A critical challenge in selective nanoparticle assembly lies in controlling the dimensionality of assemblies. Three-dimensional aggregates are readily prepared in solution, and one-dimensional assemblies can be approached by attaching micro- and nanoparticles along the length of a single DNA strand. However, at present there are no efficient methods for assembling such particles in two dimensions. While several groups have demonstrated that particle monolayers or multilayers can be assembled onto solid surfaces via DNA hybridization, to date none of them have successfully prepared freestanding two-dimensional assemblies.
Nanoparticle rafts have been prepared at liquid-air and aqueous-organic interfaces by taking advantage of entropic forces acting on repulsive particles. Unfortunately, however, these interfaces are incompatible with biomolecule stability and bioactivity, including DNA hybridization-driven or protein recognition-driven assembly.
Cells are also filled with nanometer and micron-scale compartments, or organelles, whose location and function can determine the activity of the whole cell. The biological cell can be thought of as a highly functional, complex, self-assembled structure. A typical cell carries out a bewildering number of different biochemical reactions simultaneously, and maintains vastly different chemical compositions in various spatial positions, all within microns of each other.
It would be desirable to design synthetic self-assembled architectures that mimic not only the plasma membrane but also the cytoplasm and internal structures found in biological cells. It would also be advantageous for these synthetic cells to perform typical cell functions, for example: motility, chemotaxis, specialization to form cooperative structures (i.e. tissues, organs, human beings), as well as production of minerals ranging from magnetic particles to hydroxyapatite (bone). Synthetic production of functional cell mimics has tremendous potential in medicine (e.g. drug delivery) and manufacturing (e.g. composite materials with new functions).
Accordingly, it is a primary objective of the present invention to provide a novel method and means of preparing two-phase aqueous interfaces that may be used to assemble particles and design synthetic cells.
It is a further objective of the present invention to provide a novel method and means of preparing two-phase aqueous interfaces for assembling particles using selective recognition chemistry.
It is a further objective of the present invention to provide a novel method and means of preparing two-phase aqueous interfaces for designing synthetic cells that mimic the internal structures and functions of cells.
The method and means of accomplishing each of the above objectives as well as others will become apparent from the detailed description of the invention which follows hereafter.